From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Failures of a spring leaf and dumb iron on a 20 HP 'India' chassis during a rear axle bumping test.
| Identifier | ExFiles\Box 119\2\ scan0259 | |
| Date | 1st May 1925 | |
| R.R. 493a (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/LS/LG6.5.25. 20 HP. 'INDIA' CHASSIS WITH WIDER TRACK - 56". Bumping rear axle. Drum r.p.m. 105. Cams 2". After running 17 hrs. 40 mins. near side rear spring top leaf broke 11" to rear of centre. Brinell test 388. Thickness of leaf .284". No. of XXXXXX leaves in spring 10. Dumb iron securing rear cross member to O.S. frame member sheared off where end of frame butts up to shoulder on the dumb iron. The fracture of the dumb iron was absolutely flush with end of frame member. Time run up to this breakage - 20 hrs. 5 mins. Hs{Lord Ernest Hives - Chair}/L. Swindall. | ||